Improvement in carriage-jacks



' there swag THOMAS-w'. JOHNSTON,

0F RICHMOND, MAINE.

Letters Patent No. 99,090, dated January 25,1870.

The Schedule referred to in these Letters Patent and making part of the same.

Be it known that I, THOMAS W. JOHNSTON, of Richmond, -in the county of Lincoln, and State of Maine, have made an invention of an original and useful Carriage-J ack; and do hereby declare that the following is a description thereof, taken in connection with the accompanying drawings, which forni a part of this specilication, in whichv Figure 1 is a perspective representation of my invention;

Figure 2 being a vertical and longitudinal section of the same.

The invention herein described is intended to secure, in a carriage-jack, practically, low cost, durability, and effectiveness, as well as great variation in range, the device also possessing the advantage of being susceptible-of operation by one hand of the operator.

The invention consists in the adoption of an upright sliding bar, the perpendicularity of which is maintained by a tubular post, within which it slides and is supported, the front or working-face of such bar being formed with a range of shallow teeth, and with a series of notches or depressions, the former being taken into by a tripping-pawl or pallet pivoted to the upper part of the vpost before mentioned, and the latter by a horn projecting inwardly from a long handle or lever, suspended from the pivot of the pawl, and somewhat below it, the nature and arrangement of the said lever being such that it serves the threefold purpose of a means of elevating the slide bar or riser, of releasing the gripe of the pawl upon the same, and of a brake or drag, to prevent too sudden a descent of the said slide bar and its load, otherwise ensuing from the release of the pawl, the whole being as hereinafter explained.

In the drawings before alluded to as accompanying this specification, and which illustrate my invention- A denotes an upright tubular post, the outer or front face of which is open for about one-half' its length from the top, as shown at a, the lower part of this post terminating in a broad iiat base, which serves as a steady means of support to the device.

Sliding freely within the bore of the post A, is seen a slide bar, l),this bar being of Aabout equal length with the post, and being provided at top preferably with a shelf or pad, c, for supporting the axle of a wheeled vehicle or other object which is to be raised from OE the sluface .of the earth or of a floor.

The Vfront and general face' of the bar b is serrated, or formed with a range of saw-teeth, d d, &c.`, and also with a series of notches or cavities, e e, &c., the former greatlyontnunibering the latter.

To the upper part of the post A, and so disposed as to play within its oriiice a, is situated a swinging or pendulous tripper or pawl, f, this pawl being suspended between and pivoted to ears g g, formed upon the post and at opposite sides of its orifice a, as seen at a.

The upper and rear part of the pawl j', or that part which is disposed above its point of support, is provided with an integral eccentric or cam, It, the periphery of which is abraded or serrated, in order to take a firm hold of the bar b, and prevent its clandestine descent.

B, in the accompanying drawings, represents a long lever, which is fulcrumed, near one end, to short links or bars i fi, depending from the pivot a', and upon opposite sides thereof, the fulorum of this lever' being shown at j. A'

The shorter and inner arm or horn of the lever B is capable of either entering one of the notches of the bar b, or oifabutting against the lower end of the pawl f, asV the case may be, the mode of suspending it permitting'this to be done.

In operating with the implement or jack made as above described, it is to be placed below the axle of the carriage, and-near its wheel.

`Inoved from contact with the earth or floor, the pawl f serving, by means of its eccentric, asa hold-fast, to

prevent descent of the bar l), upon releasing the pressure upon the lever.

lVhen the carriage-axle and wheel areto be lowered, l

the horn ofthe lever B is to be withdrawn from the notch of the bar which it may at the time be in, and forced against Vthe lower end or tail of the pawlf.- This action of the lever removes the hold ofthe pawl upon' the bar, and permits it and its load to fall. Should this descent of the bar and its load be too sudden and rapid, the pressure of the lever upon the pawl shouldbe maintained, thus compelling the latter to serve as a brake to retard the speed of such parts.

Owing to the length of the bar l), a great range is imparted to the movements of the same.

The device, when constructed of cast-iron, as may be done, if desirable, is very strong and durable, and may be produced at comparatively low cost, while, as before observed, all its motions may be guided by one hand of the operator.

Claims.

I claim-- 1. A carriage-jack, so called, consisting of a tubular post or its equivalent, carrying an upright toothedor notched bar, having two series of teeth or notches, as described, and provided with the pawl f and lever B, organized and operating as explained.

2. 'lhe combination of the bar l), pawl f, and lever action with the pawl f, to prevent descent of such bar, and the other being the agency whereby the intermittent elevations of' the bar are e'ected, in mm1- ner and to produce results before explained.

THOMAS W. JOHNSTON. itnesses FREDERICK CURTIS, EDWARD GRIFFITH. 

